Textile detecting device



Oct. 14, 1952 w. c. ANDERSON TEXTILE DETECTING DEVICE 2 SHEETS-SHEET 1Filed Dec. 2. 1948 M HER p. Qwzrassw Oct. 14, 1952 w. c. ANDERSONTEXTILE DETECTING DEVICE 2 SHEETS-SHEET 2 Filed Dec. 2, 1948 INVENTORWILMER C. ANDERSON Patented Oct. 14, 1952 2,613,692 TEXTILE DETECTINGDEVICE Wilmer C. Anderson, Greenwich, Conn, assignor to Deering MillikenResearch Trust, Greenwich, Conn., a nonprofit trust of Maine ApplicationDecember 2, 1948, Serial No. 63,177

14 Claims. 1

The present invention relates to weft detectors for looms and comprisesa novel device of this character which is particularly adapted for usein the weaving of very fine yarns or of yarns of low or zero twistf Whena shuttle carried bobbin is nearly depleted of weft, it is important, inorder to avoid the running out of the weft in the middle of a pick, thatthe loom be stopped or that the weft supply be replenished either-bysubstitution of a fresh bobbin for the exhausted bobbin in the shuttleor by substitution of a shuttle carryin a fresh bobbin.

Modern high speed looms are equipped with fingers or feelers whichdetect near exhaustion jof the weft supply by physical engagement withthe bobbin when the lay is in the forward position. When very fine yarnis used for the weft, the yarn is unduly damaged by this repeatedcontact with the feelers. If the damage causes breakage of theyarn,there will be a large numberof loom stops during the weaving. If theyarn does not break but is damaged, inferior fabric will be woven.

To'avoid physical contact of feelers with the yarn various arrangementsinvolving the use of photoelectric devices have Previous to thepresentinvention, however, no

been suggested.

commercially feasible photoelectric Weft detector has been developed, aseach of the previously suggested arrangements failed to meet one or moreof the following essential qualifications for a practical constructionof weft detector.

There should be a relatively large change in incident light on the lightsensitive element of the photoelectric cell as weft nears depletion.

'The detector should operate with bobbins or quills of substantiallystandard construction. Slotted quills are relatively weak and tend tocrimp the yarn in contact with the slots. Special jforms of quills addto the cost of the equipment. The construction should be compact andhave .no parts mounted on the law for movement therewith.

invention meets each of the above requirements as will be apparent asthe description proceeds. The detector signifies weft depletion when theintensity of light incident on the sensitive element of a photoelectriccell decreases sufficiently light is obtained for signifyin weftdepletion. The detector includes blanking means for preventing actuationof the device when the shuttle is not in viewing position. These means,in the preferred embodiment of the invention, comprise a mirrorpositioned to reflect light to the photocell except when the shuttle isin viewing position and a shuttle engaging finger for automaticallymovin the mirror from light reflecting position when the shuttle is inthe left hand box and the lay approaches the extreme forward position.

The detector is of compact, simple and sturdy construction, can bereadily mounted on the frame of a loom and has a relatively long usefullife. The circuit requires but few elements and is readily adjustablefor change of sensitivity. As two lamps are preferably included in thecircuit, either one of which alone provides sufficient light forillumination of the photoelectric cell, the possibility of falseindication of weft depletion is rendered almost nil. In the event offailure of any other part of the circuit the weft on the bobbin will runout and the loom will stop under its regular stop motion.

For a better understanding of the invention reference may be had to theaccompanying drawings in which one specific and preferred embodiment ofthe invention is illustrated.

. Fig. 1 'is a circuit diagram detector; g Fig. 2 is a side view of thedetecting unit, outlet box and the supportin bracket therefor;

Fig. 3 is a bottom plan view of the detecting unit showing the mountingof the reflecting mirror and control finger therefor;

" Fig. 4 is a view of the detector unit taken'from the left of Fig. 2with part of the casing broken away to show the relative locations ofthe exciting lamps and photoelectric cell; some strucof the new weft'tural parts being omitted for simplicity;

Figs. 5 and 6 are side views, partly diagrammatic showing how the mirroris retracted when tector includes a step down transformer 2, the

ends of the primary of which are connected, through suitable fuses t0 tprongs, 5a and 6b, of a three-pronged plug 6. A pair. of parallelconnected low voltage exciter lamps, 8 and I0, are connected in serieswith a resistor ll across the secondary of transformer 2. A gas filledtube 12, indicated as a tetrode, has its anode conheated through thewindings of a relay M and one of the fuses to prong 6a and its cathodeconnected through a resistor 16 and the other fuse to prong 6b. Thecathode heater is connected across the secondary of the transformer andthe control grid is connected through a resistor l8 to 3 a movable tap26 on a resistor 22. Resistors 22 and I6 and a third resistor 24 areconnected in series across the prongs 6a and 6b. A photoelectric cell 28has its anode connected to the control grid of tube [2 and its cathodeconnected to the prong 6b. The third prong 6c of the plug 6 is connectedto a front contact 1411 associated with the armature 30 of relay 14, asuitable condenser 32 being connected across the leads to the armatureand front contact of the relay to prevent sparking. A condenser 34 isconnected across the relay winding.

The plug 6 is adapted to be inserted into a socket 36 with its prongs6a, 6b and 60 connected, respectively, to terminals 36a, 66b and 360 ofthe socket. Terminals 36a and 36b are connected, respectively, to linesL1, L2, which may be, and preferably are, 60 cycle 115 volt supplylines, line L2 being the grounded line. A solenoid 38 is connectedacross terminals 360 and 36b of the socket.

With the above described circuit, when the plug 6 is inserted in thesocket 36, the lamps 8 and ID will be lighted as alternating voltagefrom the power lines will be impressed across the transformer primarythrough the mating terminals of the plug and socket. The cathode heaterof tube [2 will receive current from the secondary of the transformerand the anode of the tube will be connected through the winding of relayl4 and the plug and socket to the ungrounded power line.

The voltage of the power lines will appear also across the seriesconnected resistors 24, 22 and I6, raising the potential of the controlgrid above that of the cathode and causing tube [2 to pass current ifthe photoelectric cell 28 is not conducting current. The control grid oftube l2 will be biased to cut-01f if the photoelectric cell is renderedconductive by light from the lamps 8 and H1. As will be described inconnection with Figs. 2 through 6, the photoelectric cell is positionedout of the path of the direct beams of light from the lamps but is keptilluminated by reflected light except when weft nears depletion. Whenthe tube I2 is biased to cut-off the circuit of solenoid 38 is open atcontact l4a of relay l4. When however the cell 28 is renderednon-conducting, that is when light is not reflected thereto, relay I4 isenergized to pick up its armature 30 and thereby close the circuit ofthe solenoid 38, the circuit being from the line L1, terminal 36a ofsocket 36,

prong 6a of plug 6, armature 36, contact Ma, prong 6c of the plug, theterminal 360 of socket 36, and solenoid 38 to the ungrounded power .lineL2.

All of the elements of the circuit of Fig. 1 with the exception of theplug 6, socket 36 and solenoid 36 are adapted to be mounted within arelatively small housing and supported as a. unit on a bracket whichalso carries an outlet box for the socket 36. In Figs. 2 to 4 to whichreference may now be had constructional features of the unit are shown.In Fig. 2 the reference numeral 40 indicates the housing within whichare positioned the various elements of the circuit heretofore described.The housing has rigidly secured thereto a pair 'of'angle pieces 42 andthese pieces are supported above a plate 44 by means of shock prooftubular mounts 46. The plate 44 is mounted on the upper end 48a of aninverted L-shaped bracket 48 by means of a bolt 50 and a nut 52, thebolt passing through an elongated open ended slot 54 in the bracket end48a which permits of horizontal adjustment of the position of thehousing 40. A flexible conductor 55 connected across the angle piece 42and the plate 44 provides a ground connection for the casing. The plate44 extends only part way across the bottom of the casing (see Fig. 3)and a window 56 is provided in that part of the lower wall of the casingwhich is unobstructed by the plate 44. As shown best in Fig. 4, thelamps 8 and I6 and the photoelectric cell 28 are mounted .in the casingabove the window. Mounted in the casing beneath each lamp is a smallspherical lens 58 which confines the light from the lamp into arelatively narrow beam and prevents direct illumination of the cathodeof the photoelectric cell.

A relatively thick sheet 60 of hard rubber or the like, cut in agenerally U-shaped form, is mounted on the under side of the plate 44 bymeans of screws 62 which pass through elongated slots in the sheet. Ablock 64, also of hard rubber or the like, is mounted on the plate 44between the ends of the legs of the piece 65 so as to 'form therewith arectangular opening 66. The block 64 and the end of the piece 613 remotetherefrom have pairs of aligned passages therethrough and a pair of rods68 extend through the passages in the block 64 and into the passages inpiece 60, the size of the passages being large enough'to permit the rodsto slide freely therein. An arm 76 is fixedly mounted on the rods 68within-the opening 66. Biasing spring 12, surrounding the rods andconfined between the arm 10 and the part of the piece 66 correspondingto the'base of the U, urge the arm against the block 64. A mirror 14 issecured to the ends of rods 68 so as normally to underlie the window 56.At the lower end of the arm 10 is screw threadedly mounted ahorizontally projecting finger '16 having a rounded head 18 adapted toengage the side wall of a shuttle during operation of the device. A nut86 permits of ready horizontal adjustment of the finger 16.

The front wall of the casing 40 is provided with an outlet 82 for acable 84 comprising the leads to the plug 6. On the same wall of thecasing 46 is an adjusting screw 86 which is connected, inside thecasing, with the tap 20 on the resistor 22 so that the sensitivity ofthe unit may be adjusted externally of the casing.

Bolted to the L-shaped bracket 48, adjacent the lower end thereof, is anoutlet box 88 for accommodation of the socket 36. The box 88 has asuitable opening in the side thereof for admission of power leads andleads from a solenoid such as solenoid 38 of Fig. 1. An elongated slot9| is formed in the bracket 48 for accommodation of a bolt 93 by meansof which, and of a nut 95, the bracket may be adjustably mounted on theframe of a loom.

The above described unit is so mounted on a loom with reference to thelay and the shuttle boxes carried thereby that when the lay is in theextreme forward position, the head 18 of finger l6 protrudes into theside opening in a shuttle box as indicated in Figs. 5 and 6, wherein theleft hand shuttle box of a loom is indicated at 89, a shuttle at 9| anda bobbin at 33. When the shuttle is not in'the box the head 18 does notmeet any obstruction, as shown in Fig. 5, and hence the mirror [4remains in place beneath the window 56 of the housing. When, however,the shuttie is in the box, as indicated in Fig. 6, the head [8 isengaged by the side wall of the shuttle, finger 16 and arm I6 are movedforwardly (to the right as shown in Fig. 6) carrying the rods 68 andmirror '14 therewith and compressing the springs 12. The light from thelamps 3 and I0, assuming that the weft is not depleted, is thenreflected fromt he weft on the bobbin 93 back to the cell heretoforeindicated, the quill is painted-black,

the light deflected thereby will be insufficient to render the cell 28conducting. Consequently the potential on the control grid of tube l2will rise and the tube will pass current to energize the relay I4 andclose the circuit of solenoid 38.

Energization of the solenoid 38 may initiate a actuation of quillchanging or shuttle changing mechanism or may effect loom stoppage asdesired. In a Draper rayon loom, for example, the movable element of thesolenoid may be attached tothe lifting lever connecting rod of the quillchanging mechanism. Fig. 7 illustrates such an arrangement. In Fig. '7,the conventional lifting 1 lever connecting rod of a quill changingmechanism is indicated by the reference numeral 92 and the movableelement of the solenoid 38 is shown as connected thereto. In such typeof loom the casting, indicated at 94, ordinarily provided forthemounting of the conventional finger ,type' weft detector can beconveniently used for mounting thereon. of the L-shaped bracket 48andyalso for mounting thereof the solenoid 38.

In Fig. 7 theshuttle 9| is shown as boxed in the "leftghand box 89. Thebox is mounted on the lay 96 which reciprocates toward and away from the"detector unit as indicated by the double-ended -arro w-98. The pickeris indicated at l00,'picker stick at I02 and shipper or starter handleatI04.

The various parts of. the weft replenishing mechanism controlled by thelifting lever connecting rod 92 have not been illustrated in Fig. '7 asthey hold 38 may be considered as the relay controlling the weftreplenishing mechanism of such looms. For details of such mechanism, seepages 17 and60 of thesection on Crornpton- 8: Knowles Rayon Looms intheabove cited textbook.

From the above description of one specific em bodiment of the invention,it willbe apparent that'the new weft detector comprises asimple positiveacting device which may be economically constructed and readily mountedon a loom for control either of weft replenishing mechanism D er loomstop mechanism. The described construction permits of ready adjustmentof the parts. The level of the detector unit with respect to the lay maybe adjusted by means of the slot and bolt connection in the mountingbracket. The slot in the upper end of the bracket permits adjustment ofthe detector unit toward and away from the forward position of the lay.The screw 85 permits adjustment of the sensitivity of the circuit aftermounting on the loom and the shock mounting between the plate M andcasting protects the circuit elements from the vibrations'of are loomframe during operation. The provision of; the reflecting mirror with itsactuating finger engageable by the shuttle ensures against falseindications during the periods when the shuttle is not in viewingposition. The casing enclosing. all circuit elements affords protectionagainst should be provided with an opening for passage of the mirrorcontrolling finger therethrough but shuttle boxes ordinarily are soconstructed. As the operation of the above described device depends upona decrease in reflection of light as weft nears depletion, it is, ofcourse necessary that the detectorbe used only on looms weaving weft ofgreater defiective power than the bobbin upon which it is wound. Thisdoes not restrict the prime field of use of the new detector as fabricwoven from fine yarns having low or "zero twist, such as low denierfilament rayonfwhich is the type of yarn subject to injury whenphysically contacted by conventional feelers, is ordinarily dyedafterbeing woven and hence; the weft on the bobbin will be light incolor and have high reflective power. By suitable adjustment of thesensitivity control, however, the detector can be made to operatesatisfactorily when there is but relatively slight difference inreflectivity between the dull black bobbin and the surface of the weft.r

Obviously Various changes could'be'made in the specific constructionillustrated and described and various features could be omitted withoutideparting from thespirit of the invention'asdefined in the appendedclaims; for example instead of using a retractable reflecting mirror forI maintaining the solenoid deenergized during the periods when theshuttle is not in viewing'po'sition, switches operated by moving partsof the loom could be employed if desired either to maintain the controltube deenergized or 'to hold open the solenoid circuit, during suchperiods and such alternative arrangements is within the intended scopeof the invention. Other modifications such as the omission of one of theexcitingla'mps, or the inclusion of a pilot lampor othersignal toindicate normal or abnormal operation of the detector will occur tothose skilled in the art. The following is claimed: l 1 1. The. loomhaving a shuttle carrying a supply of weft, the combination comprising alight sensitive element, means actuated in response to a change in theillumination of said element for signifying weft depletion, a source oflight-for illuminating said element by reflection from the surface ofthe weft when the shuttle-is in one position and means including areflector effective to direct light from said source to said elementexcept when the shuttle is in said one position for preventing actuationof said signifyingmeans except when the shuttle is in said one position.2. The combination according to claim 1 wherein said last mentionedmeans comprises a reflector, means normally biasing said reflector intoa position to reflect light from said source to said element and afinger engageable by the shuttle as the shuttle moves into said oneposition for moving said reflector from said reflecting position.

3. In a loom having a shuttle carried'weft supply, a fixed source oflight, a light responsive element'in fixed position,reflecting'meansinormally positioned to reflect light from said source.to said element for illumination thereof, means responsive to adecrease in illumination of said element for signifying weft depletion;and-means actuated by normal operation of the loom for intermittentlymoving said reflecting means out of reflecting position for renderingthe illuminationof said element dependent upon light reflected from thesurface of the weft in the shuttle. 4. In a loom, the combination with aweft replenishing mechanism and a shuttle carried bobbin, of a devicefor initiating actuation of said mechanism comprising means for creatinga fixed beam of light, a light sensitive element positioned to receivelight reflected from the bobbin when the bobbin enters the beam, meanscontrolled by said element for initiating actuation of the weftreplenishing mechanism upon a decrease in the intensity of reflectedlight received by said element indicative of a depleted bobbin and meansfor preventing initiation of actuation of the weft replenishingmechanism by said last mentioned means except when the bobbin isilluminated by the beam.

5. The combination according to claim 4 wherein said element is aphotoelectric cell-and said means controlled thereby includes anelectronic tube which when energized initiates actuation of the weftreplenishing mechanism and a circuit controlling energization of saidtube, said circuit including said photoelectric cell. I

'6. The combination according to claim 5 wherein said tube has a controlgrid and said photoelectric cell is connected thereto to bias the sameto cut-off when rendered conductive by illumination.

'7. A weft detector for actuation of an element of a loom which, whenactuated, signifies deple- I tion of the weft on a shuttle carriedbobbin, comprising in combination a circuit adapted when energized toactuate said element, a source of light, a photoelectric cell adaptedwhen conductive to prevent energization of said circuit and positionedto be rendered conductive by light from said source reflected from thesurface of weft on the bobbin in one position of the shuttle and meansfor preventing energization of said circuit except when the shuttle isin said one positi on,-said last mentioned means comprising amemberbiased into a position toreflect light from said source to saidcell and means operative as the shuttle enters viewing position to movesaid member against its bias out of light reflecting position.

8. The weft detector according to claim 7 wherein said circuit includesa thermionic tube source of light, a light sensitive device fixedlypositioned out of the direct path of light from said source, movablemeans biased into a position to reflect light from said source to saiddevice, means controlled by said device and responsive to a substantialdecrease in illumination thereof for actuating said element, and meansresponsive to normal operation of the loom for moving said reflectingmeans against its bias out of light reflecting position, said lastmentioned means operating when the shuttle carried bobbin ated tosignify weft depletion and with a shuttle carried bobbin having asurface of low reflective power, said unit comprising a bracket adaptedto be mounted on the frame of the loom, a housing mounted on saidbracket, said housing having a windowin one wall thereof, circuitelements including a lamp and a light sensitive device mounted withinsaid housing adjacent said window, a light reflecting member carried bysaid bracket and movable into and out of position to reflect light fromthe lamp back through the window to illuminate said light sensitivedevice, means biasing said member into light reflecting position, afinger rigidly connected with said member for moving the same againstsaid biasing means upon engagement with a regularly moving loom part,and means for connecting the circuit elements in said housing with themeans for signifying weft depletion for actuation thereof upon apredetermined decrease in illumination of said light sensitive device.

12. The weft detecting unit according to claim 11 wherein the window isin'the lower wall of the housing and said bracket is so mounted on theframe of the loom that the window in the housing overlies the shuttlewhen the lay is in the forward position and wherein said finger ispositioned for engagement by the shuttle as it moves into viewingposition whereby the light sensitive device will be illuminated duringthe period when the reflecting member is moved out of reflectingposition only when sufiicient weft is on the bobbin to reflect lightthereto.

13. Theweft detecting unit-according to claim 11 wherein one of saidcircuit elements is a thermionic tube having a control grid, and saidlight sensitive device is a photoelectric cell connected to the controlgrid to bias the same to cut-off when rendered conductive byillumination.

14.'The weft detecting unit according to claim 11 wherein one of saidcircuit elements in said housing is adjustable for changing thesensitivity of the unit, and wherein means accessible from without thehousing are provided for adjusting said last mentioned circuit element.

WILMER C. ANDERSON.

REFERENCES CITED 7 The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,026,146 Turner Dec 31, 19352,026,147 Turner Dec. 31, 1935 2,026,148 Turner Dec. 3 1, 1935 2,026,149Turner Dec. 31, 1935 2,431,340 Payne ..4 Nov. 25, 1947 2,432,171 PayneDec. 9, 1947 2,432,793 Payne Dec. 16, 1947 2,522,101 Dion et a1 Sept,'12, 19-50

